Calculating device



' (No Model.)

A. W. TUCKER.

CALCULATING DEVICE.

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WITNEssEs:

)RM m.

UNITED STATES PATENT OFFICE.

ARGYLE WV. TUCKER, OF MIDLOTHIAN, ASSIGNOR OF ONEHALF TO VILL- 1AM T.STEXVART, OF BIG SPRINGS, TEXAS.

CALCULATING DEVICE.

SPECIFICATION forming part of Letters Patent No. 331,264, dated November24, 1885.

Application filed April 13, 1885. Serial No. $1,996.

To all whom it may concern.-

, Be it known that I, A'RGYLE V. TUCKER, of Midlothian, in the county ofEllis and State of Texas, have invented a new and useful 5 Improvementin Calculating Devices, which improvement is fully set forth in thefollowing specification and accompanying drawings, in which- Figure l isa face view of the calculating device. Fig. 2 is a View of the centraldisk,

and Fig. 3 is an edge view of the device.

The object of my invention is to provide a simple and efficientcalculating device, either for use in schools or for computing interest,or r 5 calculating measures of any kind for mill or factory use, or anyof the operations requiring a quick and accurate knowledge of figures inmultiplication, addition, division, or subtraction; and to this end itconsists in having a central disk provided on each side with a disksomewhat smaller, the three being pivoted centrally, so that the smallerdisks on the sides may be rotated independently of the central disk. Thecentral disk has twelve or more marginal figures on each side,equidistant from each other, and a column of figures extending inwardlyfrom each marginal figure. The smaller disks have twelve or moreapertures eccentrically arranged around the disk, but 0 each aperture isarranged on a direct line between the center of the disk and one of thetwelve marginal figures on the inner disk, so that the only figureexposed through the aperture is that figure which is the multiple of 5the marginal figures, all of which will nowbe set forth in detail.

In the accompanying drawings,A represents the main or central disk, andB G the disks of smaller size pivoted on opposite sides 0 so as to becapable of rotation independently of the central disk. The central disk,A, as shown morefully in Fig. 2, has on its margin, on both faces, thefigures from one to twelve. These figures are equidistant from eachother,

and instead of being limited to twelve may Y exceed that number. Thisdisk, it will be observed, has twelve columns of radiating figures, thecolumn designated by the figure 1 in the margin has the figures from 1to 12 5o successively, and the second column, desig- (No model.)

natcd by 2, has the figures from 2 to 2i, and so on, the figures in allthe columns being multiples of the figures in the margin. (See Fig. 2.)

The outer disk, B, is sufficiently small to expose the marginal figureson the central disk, as shown in Fig. 2. The outer disk, B, has also onits margin twelve figures equidistant from each other, and in the eventof the central disk having a greater number than twelve, it is necessaryfor this disk to have the same number. The disk B has a series ofapertures or openings, D, spirally arranged. There are also twelve ofthese apertures, and, as shown, they are so located that each apertureis directly in the path of the radiating line from the center to one ofthe marginal figures on the outer disk. Thus, the inner aperture D inthe disk B corresponds with or is on a line between the marginal figurel and the center, and as the disk B is rotated the aperture willsuccessively expose the concentric row of figures l 2 3 4 5 and so on inthe different radiating columns. The next aperture is located one removeor number both outwardly from the center and also around the disk,exposing the figure 12 in column 6 of the center disk. Since this sideof the cal culator is for multiplying purposes, the marginal figures onthe two disks serve as the multiplier and multiplicand, and the productis shown or exposed through'the apertures D. The disk 0 on the oppositeside is constructed and arranged in the same general way,although it maybe arranged on this plan with an intcrest-table, or with the figures ofsuitable denominations to add instead of multiplying.

In short, the disks can be adapted for an in finite variety of usesinthe way of calculating, and since it is cheap and simple in construc- 0tion and occupies but little space, it can be made of great service forthe purposes set forth.

YVhat I claim as new is 1. In a calculating device, a central diskhaving a series of radiating columns of figures, 5 all the figures ineach column being multiples of the marginal figure, in combination witha smaller disk rotating 011 the central disk, having on its margin thesame number of figures as on the margin of the central disk, and alsomarginal figures and spirally-arranged apertures for exposing thefigures in the columns of the central disk, the whole arranged as andfor the purpose substantially as herein set forth.

In testimony that I claim the foregoing I have hereunto set my hand,this 21st day of March, 1885, in the presence of witnesses.

ARGYLE XV. TUCKER.

Witnesses:

J. S. ZERBE, ROBERT 1. KER.

